From 77e5886033097d9e51e6a9d47f95086f902bd8ce Mon Sep 17 00:00:00 2001
From: Shad L. Lords <slords@mail.com>
Date: Mon, 19 Oct 2009 08:08:43 -0600
Subject: [PATCH 04/17] Allow creating/mounting degraded raid arrays

---
 fsset.py |   32 ++++++++++++++++++++++++++++++--
 raid.py  |   18 ++++++++++++++----
 2 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/fsset.py b/fsset.py
index 54753a0..ea9ba66 100644
--- a/fsset.py
+++ b/fsset.py
@@ -2466,11 +2466,20 @@ class RAIDDevice(Device):
                                                 self.minor)
 
     def raidTab (self, devPrefix='/dev'):
+        if self.level == 1:
+            nDisks = max(2, self.numDisks)
+        elif self.level == 5:
+            nDisks = max(3, self.numDisks)
+        elif self.level == 6:
+            nDisks = max(4, self.numDisks)
+        else:
+            nDisks = self.numDisks
+
         entry = ""
         entry = entry + "raiddev		    %s/%s\n" % (devPrefix,
                                                                 self.device,)
         entry = entry + "raid-level		    %d\n" % (self.level,)
-        entry = entry + "nr-raid-disks		    %d\n" % (self.numDisks,)
+        entry = entry + "nr-raid-disks		    %d\n" % (nDisks,)
         entry = entry + "chunk-size		    %s\n" %(self.chunksize,)
         entry = entry + "persistent-superblock	    1\n"
         entry = entry + "nr-spare-disks		    %d\n" % (self.spares,)
@@ -2480,6 +2489,10 @@ class RAIDDevice(Device):
                                                         device)
             entry = entry + "    raid-disk     %d\n" % (i,)
             i = i + 1
+        while i < nDisks:
+            entry = entry + "    device            dev/null\n"
+            entry = entry + "    failed-disk    %d\n" % (i,)
+            i = i + 1
         i = 0
         for device in [m.getDevice() for m in self.members[self.numDisks:]]:
             entry = entry + "    device	    %s/%s\n" % (devPrefix,
@@ -2492,6 +2505,15 @@ class RAIDDevice(Device):
         def devify(x):
             return "/dev/%s" %(x,)
         
+        if self.level == 1:
+            nDisks = max(2, self.numDisks)
+        elif self.level == 5:
+            nDisks = max(3, self.numDisks)
+        elif self.level == 6:
+            nDisks = max(4, self.numDisks)
+        else:
+            nDisks = self.numDisks
+
         node = "%s/%s" % (devPrefix, self.device)
         isys.makeDevInode(self.device, node)
 
@@ -2504,12 +2526,18 @@ class RAIDDevice(Device):
             args = ["--create", "/dev/%s" %(self.device,),
                     "--run", "--chunk=%s" %(self.chunksize,),
                     "--level=%s" %(self.level,),
-                    "--raid-devices=%s" %(self.numDisks,)]
+                    "--raid-devices=%s" %(nDisks,)]
 
             if self.spares > 0:
                 args.append("--spare-devices=%s" %(self.spares,),)
             
             args.extend(memberDevs)
+
+            i = 0
+            while self.numDisks + i < nDisks:
+                args.append("missing")
+                i = i + 1
+
             log.info("going to run: %s" %(["/usr/sbin/mdadm"] + args,))
             iutil.execWithRedirect ("/usr/sbin/mdadm", args,
                                     stderr="/dev/tty5", stdout="/dev/tty5")
diff --git a/raid.py b/raid.py
index 28829ed..aecd762 100644
--- a/raid.py
+++ b/raid.py
@@ -125,7 +125,17 @@ def scanForRaid(drives):
     raidList = []
     for key in raidSets.keys():
 	(level, totalDisks, mdMinor, devices) = raidSets[key]
-	if len(devices) < totalDisks:
+        if len(devices) == totalDisks - 1 and level in (1, 5, 6):
+             log.info("missing components of raid device md%d.  The "
+                      "raid device needs %d drive(s) and only %d (was/were) found. "
+                      "This raid device will be started in degraded mode.", mdMinor,
+                      totalDisks, len(devices))
+        elif len(devices) == totalDisks - 2 and level == 6:
+             log.info("missing components of raid device md%d.  The "
+                      "raid device needs %d drive(s) and only %d (was/were) found. "
+                      "This raid device will be started in degraded mode.", mdMinor,
+                      totalDisks, len(devices))
+        elif len(devices) < totalDisks:
             log.warning("missing components of raid device md%d.  The "
                         "raid device needs %d drive(s) and only %d (was/were) "
                         "found. This raid device will not be started.", mdMinor,
@@ -185,11 +195,11 @@ def get_raid_min_members(raidlevel):
     if isRaid0(raidlevel):
         return 2
     elif isRaid1(raidlevel):
-        return 2
+        return 1
     elif isRaid5(raidlevel):
-        return 3
+        return 2
     elif isRaid6(raidlevel):
-        return 4
+        return 2
     elif isRaid10(raidlevel):
         return 2
     else:
-- 
1.7.1